The growth characteristics, cross-compatibility, disease-resistance and fruit quality of the intergeneric hybrids between apple and Japanese pear, bred by the means of embryo culture, it's adventitious bud induction and seedling to cross reciprocally, were studied in order to introduce usefull genes of apple or pear to each other.Morphological characteristics of these hybrids were similar to those of mother plants in general. However, the genes from the father plants like an anthocyanin development and an improvement of the graft-compatibility to the rootstocks of father's genus were introduced to the hybrids.The hybrids produced many flower buds were pollinated with the pollens of pear and apple cultivars, and each cross-compatibility was tested. Many hybrids showed the cross-imcompatibility with many pear and apple cultivars and the complicated cross-compatibility as the compatibility differed among the cultivars with same S-gene.The investigation of the inheritance of susceptibility to black spot disease of Japanese pear and Alternaria blotch of apple in these hybrids revealed the interesting segregation in hybrids of Japanese pear to cross apple pollen, and the resistance against both diseases in the hybrids of apple to cross Japanese pear pollen, and the resistance against both diseases in the hybrids of apple to cross pear pollen. One hybrid of apple to cross pear pollen showed the resistance to apple scab disease, and three hybrids of pear to cross apple pollen showed the resistance to pear scab disease.The fruit characteristics were also similar to those of mother plants. Some hybrids bearing with big fruit and high sugar content may be hopeful. Some of them showed the intermediate composition of sugars and organic acids.